1. Field of the Invention
This invention relates to novel cephamycin derivatives and a process for preparing the same. More particularly, this invention relates to 7-(5-acylamido-5-carboxyvaleramido)-3-(.alpha.-methoxy-p-acyloxycinnamoylo xymethyl)-7-methoxy-3-cephem-4-carboxylic acids represented by the formula (I) ##STR1## wherein R represents an alkyl group having 1 to 4 carbon atoms which may be substituted with halogen atoms; an aryl group; an arylalkyl group having 1 to 4 carbon atoms in the alkyl moiety; an alkoxy group having 1 to 4 carbon atoms which may be substituted with halogen atoms; or an arylalkoxy group having 1 to 4 carbon atoms in the alkoxy moiety; the aryl moiety of the aryl, arylalkyl or arylalkoxy group being optionally substituted with halogen atoms, and the salts thereof, and a process for preparing the compounds of the formula (I).
2. Description of the Prior Art
7-(5-CARBOXYVALERAMIDO)-3-(.alpha.-METHOXY-P-HYDROXYCINNAMOYLOXYMETHYL)-7-M ETHOXY-3-CEPHEM-4-CARBOXYLIC ACID OF THE FORMULA (II) hereinafter given has been isolated as a fermentation product of some kinds of Streptomyces by Stapley as disclosed in Japanese Patent Application OPI Nos. 3286/1971 and 1876/1972. However, as is described in the reports of Antimicrobial Agents and Chemotherapy 2, 132-135, 1972, it is very difficult to obtain the compound of the formula (II) in a highly purified state since the compound is relatively unstable and the yield of the compound has been reported to be very low, i.e., about 10 to 15% at best.
As a result of various investigations on a method for easily isolating the compound of the formula (II) from the fermentation broth or a filtrate obtained from the fermentation broth, it was found that the compound of the formula (II) can be isolated effectively and stably by a solvent extraction method in the form of novel acyl derivatives having the formula (I) while retaining the antimicrobial activity of the parent compound of the formula (II) and that the N-acyl derivatives so obtained can be used as raw materials for the synthesis of various antimicrobial agents, for example, Cefoxitin as hereinafter described in greater detail.